#include<bits/stdc++.h>
using lint=long long;
using real=long double;
void debug_impl(){std::cerr<<'\n';}
template<class Head,class...Tail>void debug_impl(Head head, Tail... tail){std::cerr << " " << head;debug_impl(tail...);}
    template<class Container,class Value=typename Container::value_type,std::enable_if_t<!std::is_same<Container,std::string>::value,std::nullptr_t> = nullptr>
std::ostream&operator<<(std::ostream&os,Container const&v)
{os<<"{";for(auto it=v.begin();it!=v.end();it++){os<<(it!=v.begin()?",":"")<<*it;}return os<<"}";}
    template<template<class...>class Tuple,class...Args,std::size_t...Inds,std::size_t=std::tuple_size<Tuple<Args...>>::value>
std::ostream&tuple_output_impl(std::ostream&os,const Tuple<Args...>&tuple,std::integer_sequence<std::size_t,Inds...>)
{os<<"(";(void)std::initializer_list<int>{((void)(os<<(Inds>0?",":"")<<std::get<Inds>(tuple)),0)...};return os<<")";}
    template<template<class...>class Tuple,class...Args,std::size_t=std::tuple_size<Tuple<Args...>>::value>
std::ostream&operator<<(std::ostream&os,const Tuple<Args...>&tuple)
{return tuple_output_impl(os,tuple,std::index_sequence_for<Args...>());}
#define DEBUG 1
#if DEBUG
#define debug(...)do{std::cerr<<std::boolalpha<<"["<<#__VA_ARGS__<<"]:";debug_impl(__VA_ARGS__);std::cerr<<std::noboolalpha;}while(false)
#else
#define debug(...) {}
#endif
int main(){
    std::cin.tie(nullptr);std::ios_base::sync_with_stdio(false);
    std::cout.setf(std::ios_base::fixed);std::cout.precision(15);
    lint p,q,a;std::cin>>p>>q>>a;
    lint ans=-1;
    lint inf=1'000'000'000;
    if(p==q){
        ans=a==0?0:inf;
    }else if(p<q){
        lint dif=0;
        for(lint i=1;i<100;i++){
            dif+=p*i/100>=q*i/100+a;
        }
        ans=inf-dif;
    }else{
        lint l=a==0?0:(a-1)/(p-q)*100;
        ans=l;
        for(lint i=l+1;i<=std::min(inf,l+99);i++){
            ans+=p*i/100<q*i/100+a;
        }
    }
    std::cout<<ans<<'\n';
}